Tutors Answer Your Questions about Quadratic Equations (FREE)
Question 203897: please explain to me how you decide which sign (positive/negative)is assigned to each of the factored parts:
Solve: 3x^2 = 2 - x. My text shows the factor as (3x-2) (x+1)= 0 I thought that when the constant is negative (i.e. 3x^2 + x - 2 = 0), you need a positive & negative sign. You determine which by assigning the sign of the "b" constant to the larger absolute value.
Click here to see answer by jim_thompson5910(28476) |
Question 203897: please explain to me how you decide which sign (positive/negative)is assigned to each of the factored parts:
Solve: 3x^2 = 2 - x. My text shows the factor as (3x-2) (x+1)= 0 I thought that when the constant is negative (i.e. 3x^2 + x - 2 = 0), you need a positive & negative sign. You determine which by assigning the sign of the "b" constant to the larger absolute value.
Click here to see answer by scott8148(6628)  |
Question 203968: Hi guys, I was wondering whether anyone could help me to solve this quadratic equation for x: 3x^2 + 4x - 8 = 0.
Would be most appreciative if you could include steps on how to solve it also.
Thanks, -Nick.
Click here to see answer by stanbon(57214) |
Question 203971: In an hour, Phoenix and Foghorn have munched all of the viral bodies. Phoenix, never one to miss a meal, can eat the same amount of virus by itself. Foghorn, the dainter of the two phagoes, can eat the same amount of virus as its twin, but it takes 25 minutes longer.
If phoenix dined alone how long would it take to consume the viral load? How long would it take Foghorn?
Im kinda lost on this one.
Click here to see answer by Theo(3458)  |
Question 204020: I need help with one part of solution when using the quadratic formula. My textbook does not explain this part. I will list up to where I begin to get confused.
Solve: 5x^2-8x-3=0
a=5, b=-8. c=-3
-(-8)+/- sqrt(-8)^2-4(5)(-3) divided by 2(5)
8 +/- sqrt64+60 divided by 10
8 +/- sqrt124 divided by 10
this is where it gets confusing:
8+/- sqrt (4) (31) divided by 10
8+/- 2 sqrt31 divided by 10 =2(4+/- sqrt31 divided by (2)(5)
= 2/2 times 4+/- sqrt31 divided by 5 = 4+/-sqrt31 divided by 5
I do not understand what is happening during this part. Please walk me through and explain what is being done and why it is done. thank you
Click here to see answer by jim_thompson5910(28476) |
Question 204020: I need help with one part of solution when using the quadratic formula. My textbook does not explain this part. I will list up to where I begin to get confused.
Solve: 5x^2-8x-3=0
a=5, b=-8. c=-3
-(-8)+/- sqrt(-8)^2-4(5)(-3) divided by 2(5)
8 +/- sqrt64+60 divided by 10
8 +/- sqrt124 divided by 10
this is where it gets confusing:
8+/- sqrt (4) (31) divided by 10
8+/- 2 sqrt31 divided by 10 =2(4+/- sqrt31 divided by (2)(5)
= 2/2 times 4+/- sqrt31 divided by 5 = 4+/-sqrt31 divided by 5
I do not understand what is happening during this part. Please walk me through and explain what is being done and why it is done. thank you
Click here to see answer by jsmallt9(3296) |
Question 204020: I need help with one part of solution when using the quadratic formula. My textbook does not explain this part. I will list up to where I begin to get confused.
Solve: 5x^2-8x-3=0
a=5, b=-8. c=-3
-(-8)+/- sqrt(-8)^2-4(5)(-3) divided by 2(5)
8 +/- sqrt64+60 divided by 10
8 +/- sqrt124 divided by 10
this is where it gets confusing:
8+/- sqrt (4) (31) divided by 10
8+/- 2 sqrt31 divided by 10 =2(4+/- sqrt31 divided by (2)(5)
= 2/2 times 4+/- sqrt31 divided by 5 = 4+/-sqrt31 divided by 5
I do not understand what is happening during this part. Please walk me through and explain what is being done and why it is done. thank you
Click here to see answer by Earlsdon(6287) |
Question 204072: Can someone please help me , I am completely confused by this subject? I need help solving this question.
What type of solution do you get for quadratic equations where D<0? Give reason for the answer and give example of such an equation and find the solution.
Click here to see answer by feliz1965(151) |
Question 204082: Can someone help me solve this question?
Determine the number of solutions and classify the type of solutions for each of the following equations. Justify answer.
a) x^2 + 3x - 15 =0
b) x^2 + x + 4 = 0
c)sqrt2x^2 - 4x - 7 sqrt2=0
d)x^2 - 8x + 16 =0
e)2x^2 - 3x + 7 =0
f) x^2 - 4x - 77 = 0
g) 3x^2 - 7x + 6 = 0
h) 4x^2 + 16x +16 = 0
Click here to see answer by feliz1965(151) |
Question 204081: Can someone help me solve this word problem?
The Hudson River flows at a rate of 5 miles per hour. A patrol boat travels 40 miles upriver, and returns in a total time of 6 hrs. What is the speed of the boat in still water?
Click here to see answer by stanbon(57214) |
Question 204074: I am very confused by algebra and need help, can someone help me with this word problem?
A rectangular garden has dimensions of 15f by 11f. A gravel path of uniform width is to be built around the garden. How wide can the path be if there is enough gravel for 192 sq.ft ?
Click here to see answer by Earlsdon(6287) |
Question 204074: I am very confused by algebra and need help, can someone help me with this word problem?
A rectangular garden has dimensions of 15f by 11f. A gravel path of uniform width is to be built around the garden. How wide can the path be if there is enough gravel for 192 sq.ft ?
Click here to see answer by jojo14344(1512) |
Question 204107: Could someone please help me with this proble?
Determine the number of solutions and classify the type of solutions for the following equation and justify the answer.
x^2 + 3x - 15 = 0
my answer is that there are two solutions x = 2.65, -5.65 but I'm not sure how to classify the type of solution and justify it.
Click here to see answer by RAY100(1637) |
Question 204107: Could someone please help me with this proble?
Determine the number of solutions and classify the type of solutions for the following equation and justify the answer.
x^2 + 3x - 15 = 0
my answer is that there are two solutions x = 2.65, -5.65 but I'm not sure how to classify the type of solution and justify it.
Click here to see answer by solver91311(16868)  |
Question 204120: How did they come up with the quadratic formula x=-b+ b^s-4AC/2A? and what is the purpose of imaginary numbers such as -1 and i? I don't have a square root symbol so the negative 1 is to have a sqrt. sympbol and also for the problem for the quadratic formula. Thank you you knowledge is very appreciated!!!!
Click here to see answer by jim_thompson5910(28476) |
Question 203924: Can you help me with this problem?
What type of solution do you get for quadratic equations whete D < 0? Give reasons for the answer and provide an example of such a quadratic equation and find the solution of the equation.
Click here to see answer by feliz1965(151) |
Question 204052: I desperately need help! I don't understand how exactly to do these problems??
1. A rectangular garden has dimensions of 15 feet by 11 feet. A gravel path of uniform width is to be built around the garden. How wide can the path be if there is enough gravel for 192 square feet?
2. A business invests $8,000 in a savings account for two years. At the beginning of the second year, an additional $2,500 is invested. At the end of the second year, the account balance is $11,445. What was the annual interest rate?
3. The Hudson River flows at a rate of 5 miles per hour. A patrol boat travels 40 miles upriver, and returns in a total time of 6 hours. What is the speed of the boat in still water?
4. Do exponential functions only model phenomena that grow, or can they also model phenomena that decay? Explain what is different in the form of the function in each case.
5. True or false: The function "f(x) = 4x" grows four times faster than the function "g(x) = x". Explain.
6. What are the asymptotes of the functions "f(x) = 4x" and "g(x) = log5x"?
7. A cell divides into two identical copies every 4 minutes. How many cells will exist after 5 hours?
8. The level of thorium in a sample decreases by a factor of one-half every 2 million years. A meteorite is discovered to have only 8.6% of its original thorium remaining. How old is the meteorite?
Click here to see answer by feliz1965(151) |
Question 204139: I want to know if I should apply the quadratic eqution formula to this problems:
x^2 +3 - 15 =0 and x^2 + x+ 4=0. I' asking so that I'll understand what example to follow in my book , you don't have to work it out. I'm just tired of turnoing in my work with the wrong solutions and answers just because I have need to know what example to follow and where to look. I've had it with being wrong and frustrated about all of this.
Click here to see answer by scott8148(6628)  |
Question 204163: Hi I am confused by this question, it relates to a cork being released from a champagne bottle. The height in meters of the cork above the level ground at time t seconds is modelled into the equaiton. h= 1+8t-5t^2
h stands for height t stands for time.
I answered some eairler questions relating to this but am stuck on this next part.
Substitute h=1.65 into the equation h= 1+8t-5t^2, and rearrange this to the quadratic equation t^2-1.6t+0.13=0
I do not understand the question.
Thank you for your help.
Click here to see answer by Alan3354(30952)  |
Question 204163: Hi I am confused by this question, it relates to a cork being released from a champagne bottle. The height in meters of the cork above the level ground at time t seconds is modelled into the equaiton. h= 1+8t-5t^2
h stands for height t stands for time.
I answered some eairler questions relating to this but am stuck on this next part.
Substitute h=1.65 into the equation h= 1+8t-5t^2, and rearrange this to the quadratic equation t^2-1.6t+0.13=0
I do not understand the question.
Thank you for your help.
Click here to see answer by Theo(3458)  |
Question 203923: Can you help me solve this question?
Determine the number of solutions and classify the type of solutions for each of the following equations. Justify the answers.
a. x^2 + 3x - 15 = 0
b. x^2 + x + 4 = 0
c. sqrt2^2 - 4x - 7 sqrt2 = 0
d. x^2 - 8x + 16 = 0
e. 2x^2 - 3x + 7 = 0
f. x^2 - 4x - 77 =0
g. 3x^2 - 7x + 6 = 0
h. 4x^2 + 16x + 16= 0
Click here to see answer by Alan3354(30952)  |
Question 204169: I need help with a problem, could someone please help me. How do create a real life situation that fits into the equation (x+3)(x-5)=0. I know how to solve the equation, but I'm not sure how I can create a real life situation to fit the equation to express the situation as the same equation.
Click here to see answer by stanbon(57214) |
Question 204169: I need help with a problem, could someone please help me. How do create a real life situation that fits into the equation (x+3)(x-5)=0. I know how to solve the equation, but I'm not sure how I can create a real life situation to fit the equation to express the situation as the same equation.
Click here to see answer by RAY100(1637) |
Question 204170: I need help putting this word problem into equation form, can someone help me?
A business invests $8000 in a savings account for 2 years. At the beginning of the second year, an additional $2500 is invested. At the end of the second year, the account balance is $11445. What was the annual interest rate?
Click here to see answer by ankor@dixie-net.com(15622)  |
Question 204145: Please help me solve this problem.
A business invests $8,000 in a savings account for two years. At the beginning of the second year, an additional $2,500 is invested. At the end of the second year, the account ballance is $11,445. What is the annual interest rate?
Click here to see answer by Theo(3458)  |
Question 204167: One principle used by the ancient
Greeks to get shapes that are pleasing to the eye in art
and architecture was the Golden Rectangle. If a square
is removed from one end of a Golden Rectangle, as shown
in the figure, the sides of the remaining rectangle are
proportional to the original rectangle. So the length
and width of the original rectangle satisfy
L/W = W/L-W
An artist wants her painting to be in the
shape of a golden rectangle. If the length of the painting is
36 inches, then what should be the width?
So far the only thing I have is 36/w = w/36-w. I can't find an example in my book that looks like this equation. I am missing a step somewhere.
Click here to see answer by stanbon(57214) |
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